SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ddcb867863026f6342772b0ef1eb996769fbb44fabc49582882c0eabd2ce05e' 
  AND token = 'ycUgdgb4Oa0b7UMMyUBUn0l59iyJMshmSOp20zvMs/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00086

JSON explain

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