SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '306ede0603644c60fe30db365acd52268b6d3fcedd17adaa85f913873c912a5a' 
  AND token = 'VbQK7Fo1cN5VirJtIWEVKdVtR832JA/0cqWdupXOllc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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