SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2479c971af9dc6db2b351346f8bd784ab177629b47d7e7d6051bc90ca4aec43a' 
  AND token = 'u/slRS1uVsQ4g/fmqsgG4G1uVxKyGIrYphfz5H62hlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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