SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5adc0020795906cfbad99e6d2e9f9f104b727e0c023bcd2c8e6893e03ca1f2b' 
  AND token = 'DuYgU1acGm7oXIA+gjgJoNm/D67Vzkpf09oHBZQEdp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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