SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '170f8eed422ddca21741df7b6d57749b14db6625f4c874b363f39663d4bd075e' 
  AND token = 'SD6wvv4U0QD1OqGEvdTXJRsju7ZGe3DP0lrHpj90faI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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