SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd32f6bd7287ab0b87bd6305f86284ba04f5b618246ac54d05dd0324642b0eff' 
  AND token = 'IeEiPX/2/QuRgW4y1nbeQ7DsfL057v4cF1/84xrjXeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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