SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81225281b057fc6d807f9caa6ea180f8ceb3319785f997767dabb507e56e56dd' 
  AND token = 'bYUciAzIisV/uWmwzg3mDvfiVDQpENurfN/HiYogwkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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