SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8eba5dc23fec6d40a3735c8770dffe6c4367e598990c5d7d355ccb83c574a42a' 
  AND token = 'I01IbPUbjR0L8Ig985KxiA1vgmf/qzb2KjjKq9LcQ7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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