SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b112281ccd92c42ec5863732be45fcd1af14cf9930dce35399cb846dff8fdd8a' 
  AND token = 'LVZhkwJoRAv5Eowa4J2/Zg3g+3LimjXAL2Bnq34Udbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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