SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78b73ec792da6426a6c1a84cec9cb3a077ed4734f7e573b2a2ca78a12eb8b9c7' 
  AND token = 'm0HXB4dgE2+vXAIYR0+x1NYzsPBgaZUQi3pGqY2/8FY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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