SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03634c94ffb333e05bc05ce0cd41f319311d35d89a545343470b5440719786ab' 
  AND token = 'nRZcRCUaKuufchJ3ENGQsaQ0s/09FHjeIKG37iCupnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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