SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7576efb83a458d25e173953fb29a4f395f20d14a3cdfd8194ae69221baff4a08' 
  AND token = 'Og19fflJxkT+PABXmLDwUk5Q4THRozj4MqEY1rXpZOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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