SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f31966cadbd682e7e522f3efdeef52cca8c67ea900e6301fa8358c6ea442b9af' 
  AND token = 'UPwr/MG04lK1/fRH8uS+TYhiwfZ0/ltJj9hcGTtDvcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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