SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7bdfedc5a1ac7fe52d05a6689222ef6c828396e61dd7e03f0cc25abc825eff1' 
  AND token = 'Q+ovQAf7KUAGT1PzwG6c/8UB1Fm27j/ASHHecQWuTg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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