SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34c24dc46281bfb3e67a33d9f93552bed83cf7a1fabfba67d006d2143b3f9574' 
  AND token = 'xYJEBQbSoUpu6EXGIHZONGaf83+TQ12/qma349xhQgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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