SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9aba6ffe0292ff5cc9e6e9461e187d2465b2c5dfc0e65a1fd8cf3565893eeea' 
  AND token = 'sAmYvj/SL8gfseWiNUR2Dw1wlDgJHbtGAMDxrWlAplA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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