SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6dc098f5f3c882357cf06c3e3532e23eba7791b368633c2ce3bfac14698c017' 
  AND token = 'NyuKBClhDuRKwO9pBLnOaTogklqtIXYUlUL83oANGR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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