SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '524117fb2b980d6b15d6d7263e621f24b827e0854f30a5fc6ddb8eca672ceb68' 
  AND token = 'OODmUDo8v17hJeLNQnJFOr/uJsh1OGaC8oJdMCYuRJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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