SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbdd59e37076aeb2dad9eca3a976aef489e76209f0ce5085ef20860be6616676' 
  AND token = 'vsMsJuV6O/h/pS5LjhdEWD00BTuJyfRziyyIftDDqUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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