SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '006894632bd4e4dafbbde81258343a29669278146a2d7aa3811190ba6bfb660d' 
  AND token = 'ryb4e0qf6hdxCVfZ3Sgi8G35+TSA40kmItpnKG93oP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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