SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '506c32dcde61fd1065b9c037ee5539f5efc76c73734f5bca8df851e4efcf92b6' 
  AND token = '+w/bgUOEyxZWL0zCMzsROHqYOhTdia3lYEbn/g85jDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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