SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14545e10cc1580b99bc22262399719d425ed3339f364b710b39eaeea8c9063b4' 
  AND token = 'UlzUX4OErz5FQXRMSPK6XKT9at4hwHinhSNpfV7GMPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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