SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db0a019034f471457ca2158a0297bc2e5c3f9b009390e1c92e1cee98d2f411b3' 
  AND token = 'IAQaUfsWvHGGBqskdqdA5Halpwpm9ePHiG2A11UU+u4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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