SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2e916efc265e948a347c2bb1d9dc84a426cef32606c7b842b409097d059da9d7' 
  AND token = 'mWDug2GlDD5+9Inaqc/V9ZfhNiM1+Vz0MNSbP2FFJ3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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