SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39eab688cf371b3d92487ae543fa627b2013b47d6ad2e163f2343961d9ad5d9d' 
  AND token = '1vk/Xswk5LV1AYzqihikVugJeyO8d20urkU1YK5IQro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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