SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4062ed2e90701b1894695315dda6b14af1866cb39796cf621d4e67c8c08e3d7c' 
  AND token = 'uIuoYxhfiTB/YAu16ujeWigC1zqNzqblGlWuPb7CPFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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