SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14fd8061bf998389c166adcb180dd8df26a9e2f6a3ef58d3df8370d9b27df5b1' 
  AND token = 'imsT6T/VVBzPsR2UANGWTmUiaDucBoLfXghbjVWq+8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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