SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65c675d02ed003a1f014477bd3274fee6a617fa51b62a650e1f90e0768becd81' 
  AND token = 'InLW+IJO1UwJvgRcSXSOYyBLjNtuQvYUb2DupHRy+7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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