SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7db6415ee180ef06d0cd97f5d1157825e2246fa9496a1c204f236f8841ec947a' 
  AND token = 'OpDQLhR/bfD9e1lAAF2prdqs5NJe8ozWPEEGuAfC/rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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