SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3d7b0693ee15ea5a620f2fd586ab33c2a900528e042b79eb9483834c8468221' 
  AND token = '2G+pvR07oL5i0iuQibAG1iLNBYEiUQ3xLKTOAtu/rxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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