SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adf24d4cbb5c5236459619f6f1eb826562cf064235fc8bad64487682a2d9f2b2' 
  AND token = 'sNPlpmBnCE/w93BdrPp+yRQLvCB/IRm/AXuwI4JyO7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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