SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '913f6a1657289c99609843ab69d94521cbb14d58128d1c6a22dd963c5b241010' 
  AND token = 'iWUvss33viLbAhgTKHBtcgIbo63M0oPgwXW91AokyRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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