SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec44395bb2b0cd67b0573bc153d2fbefa179b3dc097505197ea8d5d8081b4641' 
  AND token = 'RNYGSUTSohDL9NQ80pA9GEc/fLCKdh2JTHaHwXHNKJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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