SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da88b32a5e46df38615472920ee12b7cae4225957cdd7964bfe5b1b7aabccc51' 
  AND token = '0dcunqvYPcykT/KokWkWHES0klfGPQiT7prYWHGjw3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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