SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e5e7bea2924ca88b2ae719f0cfa24b0804713c6e50574e6f16ead6afaad10d5' 
  AND token = 'Zgd50SMz9cASMV/pWilV2HOTD/bNw4BF42ma98qczO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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