SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5e9bb10d29eecf2dcfd214aa57eb31964a6435b0725419b51f74383d2fa8348d' 
  AND token = '5DXUtOAHU+yKMq7WgS6Mhk6b0uyeAQ7s+Naq9G/CvIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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