SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb4b5cdc390965d5d355f61a5248fbdfb5b6bd17bbd52529f86a792269cc360d' 
  AND token = 'Bj92YFNelbwrvIqGE+Ol9ariJe1DCdrxpQPacBWPfxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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