SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99df43f7282be52d997c6cf5c9d4077c5bbd46d43cac96dfb63af1deca486002' 
  AND token = 'okUH5HqgT6WWrKVCaYLuAspFpsD89DftoNS+Vsc3ZQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}