SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '752327c1f6f0f594fc2039b7bbd0bd0a5639408678ae7a04da23f9e5f98abf81' 
  AND token = 'cfHGsmLVLqUlts/R/CPm9JW1DOF4wKsxpiWU9Tr49+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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