SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aa304f95df0dcfc9ad296f221b740bd3b6b2921c2a5d9ae2b1d234e581f6398' 
  AND token = '/NEwq8oDyI1j3pnGEO6TWpPQAGC92Da4Oni8zPpWoTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}