SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bed3262aa9d8ad009845db576af32bbb0a71f36027f19f69fa1856fd1fe328d6' 
  AND token = 'TeTKJWDpXpQoCRv5ij45Fhzbbl7lk+fdM7ZcVBNxsao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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