SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d8d881ee32e4407464a58d1e204ad4a17a53186340d10f66bbfa4a0a8cb4cd4' 
  AND token = 'wo4JbLli7hLpiRkkBv2j40uL9VASHj1VQJCELAT8PZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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