SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b8045c7bf1bbf11d3bc50fba2e569fa001fa245906aeb07116f748398f016c5' 
  AND token = 'mfOO6cN+QybmTFGYl73/ByUqEHR5M+Y0VQP14aWO36s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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