SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44a69bee97415b698b5a48e28ca032f87453d79e9d4dd19f995c1a2a330f7f7c' 
  AND token = 'fs5KB0VahTGGAIDDgjX2QSN6egXfHNJLM0qpBVY/GDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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