SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72648b0b94544788e82f5c023c0792191e913a5ef9dd0f33ae4c1ce9d6d85ce8' 
  AND token = 'BrEJdy8cgassFXxrAPQ7NRBIY0+cOCZBq8ISoNGCTh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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