Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a313e5fc32a9c1cabb44c87033c4fcab51ddc2bb0284aa79d45df6acd0aa67a7' 
  AND token = 'vQLiLics8CCIVJz5Kitmj84cwFrWpFpwMU8jg3Ag5/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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