SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a98e9d23d8bb82a9d2f9ca100e325690fbdfa1b981aad28d28cb91c3815b92d2' 
  AND token = 'vSxFEXJqUHvkLy206LBEusSDf+YunkgDTROln2mkbnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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