SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39b72054c74e95848ac502f76a31ea5a7befa56d40e5502ee26600791ea102d2' 
  AND token = 'wTi1Ou7rWFIRShXoHaPesWibsZj6+D1O42SAgOEYkRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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