SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b8df00d0b011df74c499f59a2cf6070c089edd46a19868518d58de0891a6bfd' 
  AND token = 'Z0bpngLOmIrfBjvXRQRPCKXq1FrfnTlnZyk5OaCzg0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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