SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'dd02da421858a7494b99944444bb598a97769a3d79590c3b68fa86672e44037a' 
  AND token = 'ijeV5fXvDMETDG7F5CY9jvI0SoJrDiSJHrYc7NCgzN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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