SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a7b46460491ef892fd35f3b3a2f5abb33e48619fbeb0169fdcfbce1bcd6dfab' 
  AND token = 'mPUQLSBu9TjFWr39uCF14hMB9vnNgcqhI/bVFdlZBJs=' 
  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"
    }
  }
}