SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a914771e8ea2adf7428b3b3661dc3539f5d7ca90bba6d928460f93d42190589c' 
  AND token = 'CZ/+NxvMMo9/ZwSZNi54jPcUB9/2XEyr7CFZv4tHhMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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