SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '731b25cb027a26739a0407a51346b001e197b52c837b7fb67a7ed4b110e51f43' 
  AND token = 'VLLQ/+Yyb8fKJvywNnDn6W5tioYIWtS+U1lZIanl6Ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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