SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ecb87aeac6a1e074d299a753b360d44814b25f92db1436232674a4cba92fcb5' 
  AND token = 'SCZ6laQ23+PFJB79Jp26NhJgY+5VNfjBupIbdxwEwB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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