SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '305e19f3bed030d356ecd1d6f0eeeca8351bf442a719c5786cfa22919ab5c132' 
  AND token = 'VTSMSJ96caadEpFQkIUXTg3rJ1ESehiz4DzYib/mbfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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