SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f1ff4b4e970135180c077a9feb5d2c59b11f71dbd669c0904494c3441fbda28' 
  AND token = 'enm78ShdriHmTLigL/m9cFbObtAq73SMq5BiL9SsvVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}