SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c8ec6bbe1e14a0178324c111d6cfa8b93851c9b809c3093a81e95d75fc3550cb' 
  AND token = 'wFb9v/+FWXBQJzQtFI5zseqqLB2RfGHz/9xaqosLUR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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