SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b24dd22174356b452daac466eaa15f718ac9901b6f90716120384f2c86aa4e1' 
  AND token = 'v6KXP9rtacedWf9w8gvkIKBcgQpdiIEhTEPy1RVBu2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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