SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bde75cf403441793e6fb50163b72237d899554ff955c78eaa4c2422e3b13b4ec' 
  AND token = 'd55pgdevvlmoKcx6M4/SzzZRPvyYmEsJWxEwH32TOz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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