SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f530b185fbc2236950caa44f072f01d354b73f8aab37f3409413aa7addf3c396' 
  AND token = 'B416bXMKpBPepnfmWJm++a8Nr4DAH2bnKPs1PItX87o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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