SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e358aced99266156cdc45de81d3347df5407c13e30044d3a2decfa6a504e14ba' 
  AND token = 'tyAaeOiEK6K7loyseAJqsny1GJz57HLPpyvN4zgriJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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