SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d69c62038047950ba697ce7374ba32f6ec22223232950bd782f49fffb03bdf5' 
  AND token = 'eYrm0WeAm9TStAXssEACjdkVw2nJvM9NEVT38tKO7Z0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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