SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'afc9fc4f8a919e3d61ff42df3ac4b5c26054cfc5888f69c3701bb7266285ed96' 
  AND token = 'dv9T1Oq+skLj3lv4CmlLigLAuicho/lg+aVCRSsDJ9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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