SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ed6992c8ea2ce7fd062e25ad84d8f23ddbc81ee75d330dadb9fac577609e188' 
  AND token = 'c1J0R/VpCRVZ5pZRAZyA8CEvikl8PpW0SQoSUzL/CnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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