SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e3c6f46e0ac3a11b643a5d6bdf422a1ae73527dfcd3dccdd0dce411b721d86c' 
  AND token = 'oiiVSz9sNtAdNcVOBVdj0yxwHh3oV2Zy1G+8+p4ypFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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